DE 100 50 151 C1 discloses a backrest element for a seat fixture with a frame of wood, light metal, or plastic forming the edge outline. A frame has, at least in some areas, a groove introduced into the narrow side of the edge. A pouch-like covering is pulled over the frame, and has piping which corresponds to the groove when in the use position and which is introduced into the groove inside the pouch on the covering. As additional configuration of the disclosed solution, the groove receiving the piping is configured in the side edges and in the upper edge of the backrest frame. The edges of the side of the frame may be designed in the lower area to be offset slightly inward and to have no groove. In the disclosed solution, the backrest is configured to be curved to achieve optimum seating comfort and in particular to provide support for the back of a seat occupant. In addition, the frame metal is in the form of a backrest shell with mounting surfaces for the respective fabric component mounted on the front and rear sides. Mounting surfaces of plastic or leather or composite materials may be used in place of textiles. The center area is clear of the backrest element so that to this extent covering of the backrest continues without additional support. Because of the elastic configuration of the cover component, the area of the back of a seat occupant is nevertheless supported safely and comfortably during the seating process.
In the disclosed solution, the cover of the backrest is guided along the side edge component element, without undesirable movement of the cover off center, since the inner piping of the cover is guided inside the piping groove. However, the disclosed solution may not be transferred to seats, such as motor vehicle or aircraft passenger seats. For one thing, the frame structure as configured is too weak to absorb the forces arising in the event of a crash. For another, there is no assurance that in the event of application of a heavy load to the backrest structure the piping component and accordingly the cover structure would not be unintentionally pulled out of the receiving groove in the side edges of the frame component, resulting in separation of the cover from the backrest.